I saw the original video on YouTube, it starts about 15-20 seconds earlier than this GIF. In that video, you could see the mountaintop boulder give way, then time how long it took to make it's appearance.

That fly debris helped push his car to the side to make room for the falling rock that just miraculously stopped right before it was going to pancake that guy. He should have been dead. The man upstairs is still giving that guy time.